It is well known to provide rubber-like bumper rings in cylinder type fluid motors for cushioning the piston at the end of its stroke and also for providing a seal for the joint between the cylinder and an end cap, one such arrangement being shown in U.S. Letters Patent 3,512,454. However, in such prior devices the sealing portion of the combination seal and bumper ring is not sufficiently isolated from the bumper portion to prevent undue stress and deformation from being transmitted to the sealing portion by the bumper portion when the latter is engaged by the piston.